JP2018197544A - Planetary gear system and air turbine starter - Google Patents

Abstract

To provide a planetary gear system and an air turbine starter.SOLUTION: An air turbine starter for an engine includes an inlet, an outlet, and a housing defining a flow channel extended between the inlet and the outlet to circulate a gas. A turbine member is journaled in the housing and disposed in the flow channel, and rotatably extracts mechanical power from gas flow and has a turbine output shaft. The air turbine starter further includes a planetary gear system which is connected to a turbine output shaft in a driving manner, and further includes a sun gear and a ring gear mounted on the housing in a manner that the sun gear and the ring gear are operably connected, and the sun gear includes a set of planetary gears connected to the turbine output shaft.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a planetary gear system and an air turbine starter.

  A drive mechanism such as a motor or engine can generate drive motion with a mechanism output such as a rotatable output shaft. The output shaft can provide rotational motion to another device, for example, via a rotatable drive shaft connected to the output shaft. A device that receives a rotational motion can operate using the rotational rotational motion as an energy source. In one example configuration, a gas turbine engine, also known as a combustion turbine engine, is a rotary engine that extracts energy from a flow of combustion gas passing through the engine toward a number of turbine blades. A gas turbine engine can provide at least a portion of the rotational motion to a rotating device, such as an accessory gearbox, that is utilized to power a number of different accessories. Accessories can include generators, starters / generators, permanent magnet alternators (PMA) or permanent magnet generators (PMG), fuel pumps, and hydraulic pumps.

  A planetary gear system can be utilized to drive one or more accessories including a starter by fitting the starter gear train within a compact profile envelope. The planetary gear system includes one or more planetary gears that mesh between an input gear and an output gear, the planetary gears rotating about their own axis and revolving around another axis of the gear train. Designed to.

European Patent No. 29998615

  In one aspect, the present disclosure is directed to an engine air turbine starter comprising an inlet, an outlet, and a housing extending between the inlet and the outlet to define a flow path for passing a gas flow. A turbine member is pivotally supported in the housing and disposed in the flow path, and mechanically extracts mechanical power from the gas flow and has a turbine output shaft. A planetary gear system is drivingly coupled to the turbine output shaft and operably couples a sun gear, a ring gear attached to the housing, the sun gear and the ring gear, the sun gear being coupled to the turbine output. A set of planetary gears coupled to the shaft, wherein the drive shaft is operably coupled to the engine and configured to rotate together, the planetary gear system configured to transmit torque from the turbine output shaft to the drive Transmitting to a shaft, the ring gear comprises a flexible ring gear configured to distribute a load between interfaces between the ring gear and the set of planetary gears.

  In another aspect, the present disclosure defines a sun gear, a set of planetary gears configured to mesh with the sun gear, and a gear surface configured to mesh with the set of planetary gears. A flexible ring gear including a radially inner portion and a radially outer portion, wherein the radially inner portion is spaced from the radially outer portion via a set of slots, the flexible ring gear being A flexible ring gear including a set of bridges located between the set of slots and connecting the radially inner portion and the radially outer portion, wherein at least one of the set of bridges The bridge relates to a planetary gear system configured to be distorted by a load from at least one of the set of planetary gears.

  In yet another aspect, the present disclosure includes a sun gear operably coupled to an input, a set of planetary gears configured to mesh with the sun gear, and an output operably coupled to the one A flexible ring gear including a radially inner portion and a radially outer portion defining a gear surface configured to mesh with a set of planetary gears, wherein the radially inner portion is from the radially outer portion. A protruding cantilever is provided, and at least a portion of the radially inner portion forming the cantilever is configured to absorb eccentricity due to movement of at least one planetary gear of the set of planetary gears by bending. The present invention relates to a planetary gear system including a flexible ring gear.

1 is a schematic illustration of a turbine engine having an accessory gearbox and a starter in accordance with various aspects described herein. FIG. 2 is an enlarged schematic cross-sectional view of a starter according to various aspects described herein. FIG. FIG. 3 is a cross-sectional view of the starter planetary gear system of FIG. 2 in a first aspect described herein. FIG. 4 is an enlarged cross-sectional view of the planetary gear system of FIG. 3 in a normal operating state. FIG. 4 is an enlarged cross-sectional view of the planetary gear system of FIG. 3 in an overload operating state. FIG. 3 is a perspective view of the starter planetary gear system of FIG. 2 in a second embodiment described herein. FIG. 6 is an enlarged cross-sectional view of the planetary gear system of FIG. 5 in an unloaded operation state. FIG. 6 is an enlarged cross-sectional view of the planetary gear system of FIG. 5 in a load operating state. FIG. 4 is a perspective view of the starter planetary gear system of FIG. 2 in a third aspect described herein. FIG. 8 is an enlarged cross-sectional view of the planetary gear system of FIG.

  The present disclosure relates to a drive mechanism that generates motion in the form of a rotating shaft coupled to a rotating device, specifically a planetary gear system coupled to a rotating shaft for a starter of a turbine engine. It is desirable to make the gear load symmetrical at the interface between the input gear and the output gear of the planetary gear system. Although the examples described herein are directed to the application of turbine engines and starters having a planetary gear system, the present disclosure can be applied to any implementation that includes a planetary gear system.

  Any reference to direction (eg, radial, top, bottom, top, bottom, left, right, side, front, back, top, bottom, top, bottom, vertical, horizontal, clockwise, counterclockwise) Are merely used for identification purposes to assist the reader in understanding the present disclosure, and are not particularly limiting regarding the location, orientation, and use of the present disclosure. References to connections (eg, attached, coupled, connected, and joined) are to be interpreted broadly and unless otherwise indicated, intermediate members and elements between a group of elements Relative movement between can be included. Thus, reference to a connection does not necessarily mean that the two elements are directly connected and in a fixed relationship to each other. The drawings illustrated are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying drawings can be variously changed.

  As used herein, the term “forward” or “upstream” refers to movement in a direction toward the engine inlet, or a component that is relatively close to the engine inlet as compared to another component. The term “rear” or “downstream” refers to the direction toward the rear or outlet of the engine relative to the engine centerline. Further, as used herein, the term “radial” or “radially” refers to a dimension extending between the central longitudinal axis of the engine and the engine perimeter. Further, it should be further understood that a “set” can include any number of each described element, including only one element.

  Referring to FIG. 1, a starter motor or air turbine starter 10 is schematically shown coupled to an accessory gearbox (AGB) 12, also known as a transmission housing, both mounted to a turbine engine 14, such as a gas turbine engine. ing. This assembly is commonly referred to as an integrated starter / generator gearbox (ISGB). The turbine engine 14 includes an air intake having a fan 16 that supplies air to the high pressure compression region 18. The air intake with the fan 16 and the high pressure compression region are collectively known as the “cold section” of the turbine engine 14 upstream of combustion. The high pressure compression region 18 supplies high pressure air to the combustion chamber 20. In the combustion chamber, high pressure air is mixed with fuel and burned. The hot pressurized combustion gas passes through the high pressure turbine region 22 and the low pressure turbine region 24 and is then exhausted from the turbine engine 14. As the pressurized gas passes through a high pressure turbine (not shown) in the high pressure turbine region 22 and a low pressure turbine (not shown) in the low pressure turbine region 24, the turbine extracts rotational energy from the gas stream passing through the turbine engine 14. To do. The high pressure turbine in the high pressure turbine region 22 can be coupled by a shaft to a compression mechanism (not shown) in the high pressure compression region 18 thereby providing power to the compression mechanism. The low pressure turbine may be coupled to the air intake fan 16 by a shaft, thereby providing power to the fan 16.

  The turbine engine may be a turbofan engine, such as the General Electric GEnx or CF6 series engines commonly used in modern civil and military aviation, or various other known such as turboprops or turboshafts. It may be a turbine engine. The turbine engine may also have an afterburner that burns an additional amount of fuel downstream of the low pressure turbine region 24 to increase exhaust gas velocity and thereby increase thrust.

  AGB 12 is coupled to turbine engine 14 in either high or low pressure turbine regions 22, 24 by mechanical power take-off 26. Mechanical power take-off 26 includes a plurality of gears and means for mechanically coupling AGB 12 to turbine engine 14. In normal operating conditions, power take-off 26 converts power from turbine engine 14 to AGB 12 and powers aircraft accessories such as, but not limited to, fuel pumps, electrical systems, and cabin environmental controls. . The air turbine starter 10 may be mounted outside either the air intake area including the fan 16 or the core near the high pressure compression area 18.

  Referring now to FIG. 2, the air turbine starter 10 that can be attached to the AGB 12 is shown in more detail. In general, the air turbine starter 10 includes a housing 30 that defines an inlet 32, an outlet 34, and a flow path 36 extending between the inlet 32 and the outlet 34 for passing a gas flow. In one non-limiting example, the gas is air and is supplied either by a ground working air cart, an auxiliary power unit, or a cross bleed start from an already running engine. The air turbine starter 10 includes a turbine member 38 that is pivotally supported in the housing 30 and disposed in the flow path 36, and mechanically extracts mechanical power along the flow path 36 from the gas flow. The gear box 42 is mounted in the housing 30. Further, the gear train 40 disposed in the gear box 42 and drivingly coupled to the turbine member 38 can be rotated.

  The gear train 40 includes a planetary gear system 44 having a ring gear 46 and a set of planetary gears 48 that can rotate about a sun gear 70. The turbine shaft 50 is coupled to the sun gear 70 of the gear train 40 to the turbine member 38 and can transmit mechanical power to the gear train 40. The turbine shaft 50 is coupled to the gear train 40 and is rotatably supported by a pair of turbine bearings 52. The gear train 40 is supported by a pair of carrier bearings 53. The gear box interior 54 includes a lubricant, including but not limited to grease or oil, to lubricate and cool machine components contained within the gear train 40, ring gear 46, and bearings 52, 53, and the like. Can be included.

  The gear box 42 has an opening 56 through which the turbine shaft 50 connects to the sun gear 70, thereby rotating the planetary gear 48, which pushes the ring gear 46 and rotates the planetary arm 57. The planetary arm 57 couples the planetary gear system 44 to the drive shaft 64 via the carrier shaft 58. The carrier shaft 58 passes through a clutch 60 that is attached and supported by a pair of spaced bearings 62. The drive shaft 64 extends from the gear box 42 and is coupled to the clutch 60 and is supported by a pair of spaced bearings 62. Drive shaft 64 is driven by gear train 40 and, as a non-limiting example, is coupled to AGB 12 via output shaft 65 so that drive shaft 64 provides drive motion to AGB 12 during a starting operation.

  The clutch 60 can be any type of shaft interface portion that forms a single rotatable shaft 66 comprising a turbine shaft 50, a carrier shaft 58, and a drive shaft 64. The shaft interface portion can be by any known coupling method, including but not limited to gears, splines, clutch mechanisms, or combinations thereof. An example of a shaft interface portion is disclosed in General Electric US Pat. No. 4,281,942, which is incorporated herein by reference in its entirety.

  The starter 10 can be formed by any known material and method including, but not limited to, die-casting of high strength lightweight metals such as aluminum, stainless steel, iron, or titanium. The housing 30 and gear box 42 can be formed with a thickness sufficient to provide adequate mechanical rigidity without adding unnecessary weight to the air turbine starter 10 and thus the aircraft.

  The rotatable shaft 66 can be any known material including, but not limited to, extrusion or machining of high strength metal alloys such as those including aluminum, iron, nickel, chromium, titanium, tungsten, vanadium, or molybdenum. It can be configured by a method. The diameters of turbine shaft 50, carrier shaft 58, and drive shaft 64 may be fixed or may vary along the length of rotatable shaft 66. The diameter can be varied to accommodate not only the spacing between the rotor and stator, but also different sizes.

  As described herein, the air supplied along the flow path 36 rotates the turbine member 38 to drive the rotation of the rotating shafts 50, 58, 64. Therefore, during the starting operation, the starter 10 can be a drive mechanism of the turbine engine 14 through the rotation of the rotary shafts 50, 58 and 64. Thereafter, since the clutch 60 can prevent the remaining rotation shafts 50, 58 and 64 from rotating, the engine 14 drives the starter 10 instead and drives only the drive shaft 64.

  Many other possible examples and configurations in addition to those shown in the above figures are contemplated by the present disclosure. Furthermore, the design and arrangement of various components such as AGB 12, power take-off 26, or starter 10 or components thereof can be reconfigured to allow many different in-line configurations.

  Referring to FIG. 3, the planetary gear system 44 is shown in more detail and it can be seen more clearly that the sun gear 70 is coupled to the turbine shaft 50. The set of planetary gears 48 is shown as three planetary gears surrounding, but not limited to, the sun gear 70. An inner interface 72 is formed where the sun gear 70 contacts a set of planetary gears 48. It is contemplated that the sun gear 70, the set of planetary gears 48, or both the sun gear 70 and the set of planetary gears 48 are pinion gears as non-limiting examples. The pinion gear is a circular gear and typically refers to the smallest of the gears of the planetary gear system 44 or can be the drive gear of the planetary gear system 44. As a non-limiting example, the sun gear 70 is shown as a pinion gear.

  The ring gear 46 circumscribes the planetary gear 48. Ring gear 46 includes a radially inner portion 76 that defines a gear surface 78. An outer interface 80 is formed, where a set of planetary gears 48 mesh with a gear surface 78 of the ring gear 46. The ring gear 46 is mounted in the gear box 42 at the radially outer portion 74 so that the ring gear 46 becomes a stationary component of the starter 10.

  According to aspects of the present disclosure, the ring gear 46 can be considered a flexible ring gear 82. More specifically, a set of slots 84 are provided between the radially outer and inner portions 74, 76 of the ring gear 46. Each set of slots 84 may include a substantially circumferential portion 86 that terminates in a tip portion 88 provided in the radially outer portion 74 of the ring gear 46. Although shown as having eight slots, the set of slots 84 can include any number of slots, including a single slot, and the set of slots 84 shown in FIG. It is for the purpose of, and is not meant to be limiting.

  The bridge 90 is located between two of the set of slots 84 and extends from the radially inner portion 76 of the ring gear 46 to the radially outer portion 74. Bridge 90 need not be a linear bridge. For example, the bent portion 91 can be included in the bridge 90. The bend 91 defines a location where the bridge 90 connects from the substantially circumferential direction along the radially outer portion 74 to a substantially radially connection where the bridge 90 connects to the radially inner portion 76. . The bridge 90 can be included in a set of bridges depending on the number of slots 84. Although shown as having eight bridges, the set of bridges 90 may include a greater or lesser number of bridges. The set of bridges 90 shown in FIG. 3 are for illustrative purposes and are not meant to be limiting.

  A set of bumpers 92 extend from each of the radially outer and inner portions 74, 76 of the flexible ring gear 82. A set of bumpers extends into a set of slots 84. The first bumper 92 a extends from the radially outer portion 74 of the flexible ring gear 82 of the first slot 84 where the bridge 90 contacts the radially outer portion 74 of the flexible ring gear 82. The second bumper 92 b extends from the radially inner portion 76 of the flexible ring gear 82 of the second slot 84 where the bridge 90 contacts the radially inner portion 76 of the flexible ring gear 82. It is contemplated that only one bumper of the set of bumpers 92 is included and can extend from either one of the outer or inner portions 74, 76. It is further contemplated that the set of bumpers 92 is a plurality of bumpers 92 extending from one or both of the radially outer and inner portions 74, 76 of the flexible ring gear 82. The set of bumpers 92 shown in FIG. 3 are for illustration purposes and are not meant to be limiting.

  Planetary gear 48, sun gear 70, and ring gear 46 are extruded or machined from high strength metal alloys such as, but not limited to, those including aluminum, iron, nickel, chromium, titanium, tungsten, vanadium, or molybdenum. It can be constructed by any materials and methods including.

  FIG. 4A is an enlarged view of a portion of the planetary gear system 44 including the bridge 90 and bumpers 92a, 92b. A gap 94 is formed between each of the bumpers 92a, 92b and the radially outer and inner portions 74, 76 of the flexible ring gear 82. The flexible ring gear 82 is configured to distribute the load across the outer interface 80 between the flexible ring gear 82 and the set of planetary gears 48. In normal operating conditions, a set of bridges including the illustrated bridge 90 is configured to distort as needed. A set of bridges 90 absorb the concentric distortion of the planetary gear 48 so that the load is evenly distributed to the outer interface 80. While the gap 94 remains open, the set of bridges 90 is distorted, resulting in an even distribution of flexibility and load at all outer interfaces 80. The radially inner portion 76 is configured to absorb by deflecting eccentricity due to at least one movement of the planetary gear 48 of the planetary gear system 44.

  Referring to FIG. 4B, in an abnormal or overloaded operating condition, at least one of the set of bridges 90 is such that at least one end 93 of the bumpers 92a, 92b is the radially outer or inner portion of the flexible ring gear 82. It is distorted to the point which contacts 74 and 76. In the illustrated example, when the bridge 90 is distorted, both bumpers 92a, 92b move to close the gap 94, thereby closing at least a portion of the set of slots 84 and the circumferential portion 86 into the tip portion 88. Separate from. The bumpers 92a and 92b limit and control the degree to which the bridge 90 is distorted. Bumpers 92a, 92b and corresponding gaps 94 are sized according to normal operating limits. The normal operating state includes the torque and speed when the engine 14 is started. The specifications for the air turbine starter 10 disclose the maximum speed and maximum torque or stall torque. The planetary gear system 44 may have a gearbox ratio and inlet conditions that are specific to the installed air turbine starter 10. The bumpers 92a and 92b function to prevent damage to the bridge 90, to transmit load from the planetary gear 48 through the flexible ring gear 82 to the gear box 42, and to prevent damage to the flexible ring gear 82. . In an overload operating condition, the flexible ring gear 82 functions like a conventional solid ring gear so that the load continues to be transmitted without the flexibility of the ring gear 46.

  5-8 illustrate flexible ring gears 182, 282 according to other aspects of the present disclosure described herein. Since the flexible ring gears 182 and 282 are similar to the flexible ring gear 82, like parts are identified by like numbers increased by 100 and 200, respectively. It should be understood that the description of similar parts of the flexible ring gear 82 applies to the flexible ring gears 182, 282 unless otherwise noted.

  As shown in FIG. 5, the flexible ring gear 182 has a body 196 that defines a radially outer portion 174 to which the flexible ring gear 182 is attached to the gear box 42. Cantilever 198 projects axially from body 196 and defines at least a portion of radially inner portion 176. A set of planetary gears 148 is operably coupled to the flexible ring gear 182 at the outer interface 180. A gear surface 178 configured to mate with a set of planetary gears 148 extends axially along the radially inner portion 176 of the flexible ring gear 182.

  As shown in FIG. 6A, the cantilever 198 extends from the body 196 such that the cantilever 198 and the body 196 form an angle θ of 90 degrees at the starting position 200.

  Referring to FIG. 6B, the cantilever 198 provides flexibility such that the angle θ can change to the secondary position 202. The planetary gear 148 (FIG. 5) can push the cantilever 198 so that the angle θ decreases to the secondary position 202. The angle θ may be in the range of 80-90 degrees in a non-limiting example. It will be appreciated that the angle sufficient to absorb non-uniform loads by allowing angular distortion may be greater or less than 80-90 degrees. The cantilever 198 absorbs the concentric distortion of the planetary gear 148 so that the load is evenly distributed to the outer interface 180. It should be understood that the secondary location 202 is a non-limiting example and can be located in a range of locations.

  In FIG. 7, a third exemplary flexible ring gear 282 includes a body 296 from which a set of radially outer portions 274a, 274b extend. The flexible ring gear 282 is attached to the gear box 42 at both the radially outer portions 274a, 274b. A set of cantilevers 298 (FIG. 8) extends axially between the set of radially outer portions 274a, 274b to define a cavity 304. The set of cantilevers 298 defines at least a portion of the radially inner portion 276. A set of planetary gears 248 are operably coupled to the flexible ring gear 282 at the outer interface 280. A gear surface 278 configured to mate with a set of planetary gears 248 extends axially along the radially inner portion 276 of the flexible ring gear 282.

  As shown in FIG. 8, a set of cantilevers 298 extends between a radially outer portion 274a, 274b that forms a 90 degree angle α, β with the body 296 at the starting position 300, respectively. A set of cantilevers 298 provides flexibility such that the angles α, β can change to the secondary position 302. In the illustrated example, the planetary gear 148 (FIG. 5) can push the cantilever 198 so that the angle β decreases to the secondary position 302. The angles α, β can range from 80 to 90 degrees in a non-limiting example. It will be appreciated that the angle sufficient to absorb non-uniform loads by allowing angular distortion may be greater or less than 80-90 degrees. A set of cantilevers 298 absorb the concentric distortion of the planetary gear 248 so that the load is evenly distributed to the outer interface 280. It should be understood that the illustrated secondary position 302 is a non-limiting example and can occur on one or both of the cantilevers 298. Further, the secondary position 302 may be in a range of positions and is not limited to the illustrated secondary position 302. With a set of cantilevers 298, the flexible ring gear 282 provides axial variability in the load distribution of the set of planetary gears 248.

  In the finite element analysis, the flexible ring gear was found to be bent 40 to 50 times in the radial direction than the solid ring gear. In experiments where the temperature of the solid ring gear was measured compared to the flexible ring gear, the running temperature of the flexible ring gear remained 10-15 degrees below that of the solid ring gear. This increased flexibility and lower operating temperature can be translated into a starter that operates longer and operates more efficiently.

  The gear meshing flexibility reduces the peak load on the gear teeth due to non-uniform load distribution and thus extends the life of the gear system. Particularly uneven load reduction extends the life of bearing systems and support gearbox components, including planetary and carrier bearings. As gearbox component wear is reduced, the accumulation of metal shavings in the starter oil that can affect other starter components is also reduced. In addition, the planetary gear system described herein can provide weight and cost savings because the load behavior of sensitive components can be more predictable and gearbox margins can be reduced.

  Unless already described, the different features and structures of the various embodiments can be used in combination with each other as desired. The fact that a feature cannot be shown in all aspects is merely for the sake of brevity and does not imply that it is impossible. Thus, various features of different aspects can be mixed and adapted as desired to form new embodiments, whether or not the new embodiments are explicitly described. Further, although a “set” of various elements has been described, it will be understood that a “set” may include any number of each element, including only one element. Combinations or substitutions of features described herein are encompassed by the present disclosure.

  This specification discloses aspects of the invention, including the best mode, and enables those skilled in the art to practice aspects of the invention, including making and using any device or system and performing any related methods. For this purpose, an embodiment is used. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If such other embodiments have structural elements that do not differ from the wording of the claims, or include equivalent structural elements that do not materially differ from the language of the claims, It is intended to be within the scope of the claims.

DESCRIPTION OF SYMBOLS 10 Starter 12 Accessory gear box 14 Turbine engine 16 Fan 18 High pressure compression area 20 Combustion chamber 22 High pressure turbine area 24 Low pressure turbine area 26 Power take-off 30 Housing 32 Inlet 34 Outlet 36 Flow path 38 Turbine member 40 Gear train 42 Gear box 44 Planetary gear System 46 Ring gear 48 Set of planetary gears 50 Turbine shaft 52 Turbine bearing 53 Carrier bearing 54 Gearbox interior 56 Opening 57 Planetary arm 58 Carrier shaft 58 Rotating shaft 60 Clutch 62 Spacing bearing 64 Drive shaft 65 Output shaft 66 Rotating Shaft 70 Sun gear 72 Inner interface 74 Radially outer portion 76 Radially inner portion 78 Gear surface 80 Outer interface 82 Flexible ring gear 8 A set of slots 86 a circumferential portion 88 a tip portion 90 a set of bridges 91 a bend 92a a bumper 92b a bumper 93 an end 94 a gap 148 a set of planetary gears 170 a sun gear 172 an inner interface 174 a radially outer portion 176 a radially inner portion 178 Gear surface 180 Outer interface 182 Flexible ring gear 196 Body 198 Cantilever 200 Starting position 202 Secondary position 248 Set of planetary gears 274a Radial outer portion 274b Radial outer portion 270 Sun gear 272 Inner interface 274a Radial outer portion 274b Radial outer portion 276 Radial inner portion 278 Gear surface 280 Outer interface 282 Flexible ring gear 296 Body 298 Set of cantilevers 300 Starting position 302 Secondary position 304 Cavity

Claims (20)

An air turbine starter (10) for an engine (14),
A housing (30) defining an inlet (32), an outlet (34), and a flow path (36) extending between the inlet (32) and the outlet (34) for passing a gas stream;
A turbine member (38) pivotally supported in the housing (30) and disposed in the flow path (36) to extract mechanical power from the gas stream rotatably and having a turbine output shaft (50); ,
A sun gear (70, 170, 270) coupled to the turbine output shaft (50), a ring gear (46) attached to the housing (30), and the sun gear (70, 170, 270); The ring gear (46) is operably coupled, and the sun gear (70, 170, 270) includes a set of planetary gears (48, 148, 248) coupled to the turbine output shaft (50). Including planetary gear system (44),
A drive shaft (64) operably coupled to the engine (14) and configured to rotate therewith,
The planetary gear system (44) transmits torque from the turbine output shaft (50) to the drive shaft (64), and the ring gear (46) includes the ring gear (46) and the set of planetary gears. An air turbine starter (10) comprising a flexible ring gear (82, 182, 282) configured to distribute a load between interfaces to (48, 148, 248).   A radial direction in which the flexible ring gear (82, 182, 282) defines a gear surface (78, 178, 278) configured to mesh with the set of planetary gears (48, 148, 248). The air turbine starter (10) according to claim 1, comprising an inner portion (76, 176, 276) and a radially outer portion (74, 174, 274a, 274b) attached to the housing (30).   A set of flexible ring gears (82, 182, 282) positioned between the radially inner portion (76, 176, 276) and the radially outer portion (74, 174, 274a, 274b) The air turbine starter (10) of claim 2, further comprising a slot (84).   The flexible ring gear (82, 182, 282) is positioned between the set of slots (84) and is positioned between the radially inner portion (76, 176, 276) and the radially outer portion (74, 174, 274a, 274b) further comprising a set of bridges (90), wherein at least one bridge (90) of the set of bridges (90) is configured to be distorted by a load. 3. An air turbine starter (10) according to 3.   The at least one bridge (90) is configured to distort without closing one slot (84) of the set of slots (84) during normal load of the planetary gear system (44). Item 5. The air turbine starter (10) according to item 4.   The air turbine of claim 5, wherein the at least one bridge (90) is configured to distort and close at least a portion of the slot (84) upon an abnormal load of the planetary gear system (44). Starter (10).   At least one extending from one of the radially inner portion (76, 176, 276) or the radially outer portion (74, 174, 274a, 274b) into one slot (84) of the set of slots (84). The bumper (92a, 92b) further includes two bumpers (92a, 92b), and the bumper (92a, 92b) has the radially inner portion (76, 176, 276) or the radially outer portion (74, 174, 274a, 274b) during the abnormal load. The air turbine starter (10) of claim 6, wherein the air turbine starter (10) is engaged with the other of the slots (84) to close the at least part of the slot (84).   At least one extending from one of the radially inner portion (76, 176, 276) or the radially outer portion (74, 174, 274a, 274b) into one slot (84) of the set of slots (84). Further comprising two bumpers (92a, 92b), wherein the bumpers (92a, 92b) are adapted to the radially inner portion (76, 176, 276) or the radially outer portion (74, 174, 274a, 274b) during abnormal loads. The air turbine starter (10) of claim 4, wherein the air turbine starter (10) engages the other of the two.   The air turbine starter (10) of claim 8, wherein the at least one bumper (92a, 92b) is adjacent to the at least one bridge (90).   The air turbine starter of claim 9, wherein the at least one bumper (92a, 92b) comprises at least two bumpers (92a, 92b) adjacent to the at least one bridge (90).   A first bumper (92a, 92b) on a first side of the at least one bridge (90) extends from the radially inner portion (76, 176, 276) and the first of the at least one bridge (90). The air turbine starter (10) according to claim 10, wherein a second bumper (92a, 92b) on two sides extends from the radially outer portion (74, 174, 274a, 274b).   The radially inner portion (76, 176, 276) comprises a cantilever (198, 298) protruding from the radially outer portion (74, 174, 274a, 274b) to form the cantilever (198, 298). The air turbine starter (10) of claim 2, wherein at least a portion of the radially inner portion (76, 176, 276) is configured to be distorted by a load. Sun gear (70, 170, 270),
A set of planetary gears (48, 148, 248) configured to mesh with the sun gear (70, 170, 270);
A radially inner portion (76, 176, 276) and a radially outer portion () that define gear surfaces (78, 178, 278) configured to mesh with the set of planetary gears (48, 148, 248). 74, 174, 274a, 274b), wherein the radially inner portion (76, 176, 276) is routed through a set of slots (84). Spaced from the radially outer portion (74, 174, 274a, 274b), the flexible ring gear (82, 182, 282) is located between the pair of slots (84) and is positioned in the radial direction. Flexible ring gears (82, 18) including a set of bridges (90) that join inner portions (76, 176, 276) and said radially outer portions (74, 174, 274a, 274b). , 282) and equipped with a,
At least one bridge (90) of the set of bridges (90) is configured to be distorted by a load from at least one of the set of planetary gears (48, 148, 248). (44).   The at least one bridge (90) is configured to distort without closing one slot (84) of the set of slots (84) during normal load of the planetary gear system (44). Item 14. The planetary gear system (44) according to item 13.   The planetary gear according to claim 13, wherein the at least one bridge (90) is configured to distort and close at least a portion of the slot (84) upon an abnormal load of the planetary gear system (44). System (44).   At least one extending from one of the radially inner portion (76, 176, 276) or the radially outer portion (74, 174, 274a, 274b) into one slot (84) of the set of slots (84). The bumper (92a, 92b) further includes two bumpers (92a, 92b), and the bumper (92a, 92b) has the radially inner portion (76, 176, 276) or the radially outer portion (74, 174, 274a, 274b) during the abnormal load. The planetary gear system (44) according to claim 13, wherein the planetary gear system (44) is engaged with the other of said at least a portion of said slot (84).   At least one extending from one of the radially inner portion (76, 176, 276) or the radially outer portion (74, 174, 274a, 274b) into one slot (84) of the set of slots (84). Further comprising two bumpers (92a, 92b), wherein the bumpers (92a, 92b) are adapted to the radially inner portion (76, 176, 276) or the radially outer portion (74, 174, 274a, 274b) during abnormal loads. The planetary gear system (44) of claim 13, wherein the planetary gear system (44) engages the other of the two.   The planetary gear system (44) of claim 17, wherein the at least one bumper (92a, 92b) is adjacent to the at least one bridge (90).   The at least one bumper (92a, 92b) with a first bumper (92a, 92b) on a first side of the at least one bridge (90) extending from the radially inner portion (76, 176, 276); 19. A second bumper (92a, 92b) on a second side of the at least one bridge (90) extending from the radially outer portion (74, 174, 274a, 274b). Planetary gear system (44). A sun gear (70, 170, 270) operably coupled to the input;
A set of planetary gears (48, 148, 248) configured to mesh with the sun gear (70, 170, 270);
A radially inner portion (76, 176, operatively coupled to an output and defining a gear surface (78, 178, 278) configured to mate with the set of planetary gears (48, 148, 248) 276) and a radially outer portion (74, 174, 274a, 274b), the flexible ring gear (82, 182, 282) comprising the radially inner portion (76, 176, 276) and the radial direction Outer portions (74, 174, 274a, 274b) are operably coupled, and the radially inner portions (76, 176, 276) are at least one of the set of planetary gears (48, 148, 248). A planetary gear comprising: a flexible ring gear (82, 182; 282) configured to absorb the eccentricity caused by the movement of the planetary gear (48, 148, 248) by bending. The stem (44).